Antenna arrays comprise an arrangement of individually radiating antenna elements for application in radio communication devices, such as wireless access points, routers and base stations, potentially along with user equipment devices such as cellular phones, laptops, and tablets. Certain operations, such as beam-steering, utilize selective operation of the phase and amplitude relationships between individual antenna elements for improving transmission and reception characteristics of the antenna array. Densely packed antenna arrays, potentially with large numbers of elements such as in Massive MIMO systems, can lead to situations in which antenna elements are situated very close to one another. Such dense arrays may be required to enable beam steering over an adequate angular range, for example. Size reduction trends and operation in higher radio frequency bands also encourage reduced spacing between antenna elements. Unfortunately, as the spacing between individual antenna elements in an antenna array becomes narrower, the mutual coupling effect between the individual elements becomes more pronounced and problematic. Mutual coupling is a typically undesired phenomenon that affects the impedance characteristics of the individual antenna elements, results in absorption of energy by nearby antenna elements, and distorts radiation and transmission patterns. Accordingly, an antenna array that reduces the effect of mutual coupling is desired.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.